Electronic Properties of Short Polynucleotides Studied Using Schottky Junctions

Deoxyribonucleic acid (DNA), the blueprint of life, has attracted recent attention concerning its potential applications in electronics. In order to realize these applications, charge transfer through the molecule has been subjected to numerous experimental and theoretical studies in the last few decades. As a result of varying experimental conditions, different electrical behaviors have been observed. The sensitive structure of DNA is influenced by extreme environmental conditions as shown in common characterization techniques. Finding a simple yet quantitative accurate method is more efficient for understanding the electronic properties of DNA. In this work, we have employed DNA-specific Schottky junctions integrated within a printed circuit board (PCB) to investigate the properties of the four nitrogenous bases of guanine (G), thymine (T), cytosine (C) and adenine (A) in short polynucleotide form. Acquisition and analysis of the current–voltage (I–V) profiles allowed measurement of selected solid-state parameters corresponding to each of the DNA polynucleotide base. While observing characteristic I–V profiles and parameters, significantly closer and higher conductive profiles were demonstrated for the purines (A and G) as compared to the highly similar profiles of the pyrimidines (T and C) which is in agreement with previous observations. The observations obtained from this work may, therefore, provide a clear conceptualization of the role of each nitrogenous base in charge transfer process through the DNA molecule and allow better understanding of the fingerprinting electronic properties of each base.